In known automobile electrical systems, complicated wiring harnesses are routed throughout the automobile, to provide power for the ever-increasing number of electrical functions. The trend in the industry is to add additional safety and convenience features to the automobile, many of which require electric power input.
Within even relative small features of an automobile, electrical system requirements can be complicated. For example, in exterior mirrors of some car designs, as many as thirteen individual wires can be required for the multiple functions associated with the new electronic mirrors. Common mirror functions, and the operators therefore functioning as electric consumers, include: mirror position adjustment with motor packs, electronic dimming of reflected light from lights of vehicles to the rear by the use of electrochromic cells, turn signal indicators in the mirror housing, memory functions for mirror positioning of multiple drivers, mirror tilt down for reverse transmission gearing, mirror heaters/defrosters, antennas, power folding of the mirrors particularly on European models, and the like.
In known electrical systems for multifunction exterior mirrors, actuators and/or controllers are positioned within the automobile doors, and a wiring harness is routed through the door into the mirror housing. Individual wires from the wire harness are routed throughout the mirror structure to the various electrical consumers associated with each of the functions. With numerous individual wires in the harnesses, multiple connectors are required, and the procedures for making the connections during assembly of the mirror are complicated and time consuming to perform. As more and more mirror functions are built into the mirrors, more and more connectors are required, increasing the possibility of a connector failure. Routing each wire properly, to avoid interference with physically moving components of the mirror, becomes more and more challenging for designers. Designers are faced with the difficulty of incorporating new and changing features with limitations on space and power availability.
It is desirable to reduce weight wherever possible in automotive designs, for the added benefits of fuel economy. Reduction in the use of wires, connectors, solder and materials and processes known to have detrimental environmental effects is also striven for. Many of these goals have been contradictory, such as increasing electrical convenience and safety functions, while reducing the use of wires, connectors and solder.
Printed circuitry techniques are known, including the printing of mirror heaters for automobiles. Printing electrical conductors on flexible material is known, to replace more expensive wires as discrete connecting elements between power supplies and electrical consumers.
A need exists to simplify electrical systems for automobiles, particularly in the relatively compact environments such as exterior mirror housings, while still incorporating a wide variety of electrical functions, with differing power demands.